<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
  console.log(location.hash);
  let iframe=document.createElement("iframe");
  iframe.src="http://localhost:3000/b.html#shangshang"
    document.body.append(iframe);
</script>
</body>
</html>